When a contaminant such as oil spills into water, as, for example, when an oil tanker runs aground or breaks apart, it is desirable to surround the spill with a containment boom as quickly as possible to prevent the oil or other contaminant from traveling far from the location of the spill and doing increased environmental damage. Various types of oil booms or curtains have been used for this purpose. A typical curtain is shown in U.S. Pat. No. 4,300,857. Such a curtain includes floats attached on each side of the curtain to keep a portion of the curtain extending above the surface of the water to Prevent the oil from splashing over the top of the curtain and escaping from the containment area. In other curtain configurations, a flotation material may be enclosed with a Pocket near the top of the curtain. A disadvantage with such curtains, however, arises in rough seas where large waves tend to push the curtain over, away from its vertical orientation, possibly allowing water and contaminants to splash over the top of the curtain.